JP2022111251A - posture holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold an upper half of the body of a seated person in a right posture.

SOLUTION: A posture holder 10 includes: a seat part 11; a backrest part 16 rising from the rear end part of the seat part 11; a first support part 17 constituting the backrest part 16, with which a central part in the lateral direction of the back 52 of the seated person 50 is brought into contact; and a pair of second support parts 18 disposed on both of the right and left sides of the first support part 17 constituting the backrest part 16, with which both of the right and left sides of the back 52 of the seated person 50 are brought into contact. The lowermost end part 17L in the upper edge part of the first support part 17 is disposed at a position lower than the uppermost end part 18U in the upper edge part of the second support parts 18.

SELECTED DRAWING: Figure 11

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a posture holder.

Patent Literature 1 discloses a posture retainer that retains the posture of a seated person in a correct state. This posture retainer includes a buttocks support that supports the buttocks of a seated person from below, and a waist support that rises from the rear edge of the buttocks support. The waist support part has a height capable of supporting the waist and the lower end of the back of the seated person, and has a substantially rectangular thick plate shape as a whole.

JP 2014-12130 A

In the above posture support, the front surface of the lumbar support (the surface that touches the waist and back) is generally planar, so the occupant can tilt the upper body left and right or twist the upper body left and right. Easy to do. However, since this posture holder cannot stabilize the upper body of the seated person in a correct posture, the seated person may spend a long time in a posture in which the upper body is tilted left or right or twisted left or right. There is concern that it will be lost.

SUMMARY OF THE INVENTION The present invention was completed based on the above circumstances, and an object of the present invention is to hold the upper body of a seated person in a correct posture.

The posture holder of the present invention is
a seat;
a backrest rising from the rear end of the seat;
a first support portion that constitutes the backrest portion and that abuts the central portion of the back of the seated person in the left-right direction;
A pair of second support portions that constitute the backrest portion, are arranged on both left and right sides of the first support portion, and make contact with the left and right sides of the back of the seated person,
A lowermost end portion of the upper edge portion of the first support portion is arranged at a position lower than an uppermost end portion of the upper edge portion of the second support portion.

The seated person sits in a state in which the relatively low center portion of the back is placed against the first supporting portion and the relatively high portions of the left and right sides of the back are placed against the second supporting portion. Since the posture retainer of the present invention supports the back of the seated person with the three support parts, it suppresses the posture of the seated person's upper body tilted left and right or twisted left and right, and corrects the upper body of the seated person. Can be held in position.

The perspective view of the posture holder of Example 1 Front view of posture holder Top view of posture holder AA line cross-sectional view with the exterior sheet omitted in FIG. BB line cross-sectional view with the exterior sheet omitted in FIG. CC line sectional view omitting the exterior sheet of FIG. DD line cross-sectional view with the exterior sheet omitted in FIG. EE line cross-sectional view with the exterior sheet omitted in FIG. FF line cross-sectional view with the exterior sheet omitted in FIG. GG line cross-sectional view with the exterior sheet omitted in FIG. HH line cross-sectional view with the exterior sheet omitted in FIG. Cross-sectional view equivalent to line AA in Fig. 2 showing the state of use of the posture holder

In the present invention, the upper end portion of the second support portion may be curved so as to warp obliquely rearward as it goes upward.
According to this configuration, there is no risk that the upper edge of the second support portion will bite into the body of the seated person when the upper half of the body of the seated person is deeply leaned against the backrest.

In the present invention, the seat portion constituting plate portion constituting the seat portion and the backrest portion constituting plate portion constituting the backrest portion are elastically displaced relative to each other with the lower end portion of the backrest portion constituting plate portion being substantially a fulcrum. The backrest portion forming plate portion includes a first support plate portion forming the first support portion and the second support portion protruding obliquely forward from both left and right side edges of the first support plate portion. and a second support plate portion constituting a second support plate portion, and a projecting dimension of the lower end side region of the second support plate portion from the first support plate portion may gradually decrease downward.
According to this configuration, when the seated person presses the upper half of the body against the backrest, the backrest is elastically displaced rearward about the lower edge of the backrest. Since the protruding dimension of the lower end region of the second support plate portion from the first support plate portion gradually decreases downward, the lower end region of the backrest-constituting plate portion is also elastically deformed. As a result, it is possible to prevent stress from concentrating on the lower edge of the backrest-constituting plate portion.

In the present invention, the first supporting surface of the first supporting portion facing the back and the second supporting surface of the second supporting portion facing the back are connected via a pair of left and right connecting surfaces. , the curvature of the first supporting surface and the curvature of the second supporting surface may be smaller than the curvature of the connecting surface in plan view.
According to this configuration, since the back does not come into contact with the joint surface having a large curvature, the upper body of the seated person can be stably supported at three points, ie, the first support surface and the pair of left and right second support surfaces. .

<Example 1>
A first embodiment embodying the present invention will be described below with reference to FIGS. 1 to 12. FIG. 4 to 6 and 12, and the downward direction in FIGS. 3 and 7 to 10 is defined as forward. 1, 2, 4 to 6, 11, and 12 are defined as upward and downward. Regarding left and right directions, the directions shown in FIGS. 2, 3, 7 to 11 are defined as left and right.

The posture holder 10 of the first embodiment is composed of a seat portion 11 that supports the buttocks 51 of the seated person 50 from below and a backrest portion 16 that supports the back 52 of the seated person 50 from behind. It has a symmetrical shape. The seat portion 11 and the backrest portion 16 are integrated. In addition, in the first embodiment, the "back 52 of the seated person 50" is defined as the back and waist of the seated person 50 (the back side and side side of the trunk in the upper half of the body).

A plan view shape of the seat portion 11 will be described. As shown in FIG. 3, in the front-rear direction, a rear-end-side support region 12R extending from the rear end of the seat portion 11 to approximately two-thirds of the front has a substantially trapezoidal shape that gradually widens toward the front. The width dimension (horizontal direction dimension) of the seat portion 11 is maximized in the rear end side support region 12R. The outer peripheral edge of the front-end support region 12F in front of the rear-end support region 12R of the seat portion 11 is composed of a pair of symmetrical front-side curved edges 13 and a front-edge gouged portion 14 . The front curved edge portion 13 continues to the left and right side edges of the rear end support region 12R and constitutes the front edge portion of the seat portion 11 . The front edge gouged portion 14 has an obtuse-angled dent in the center portion of the seat portion 11 in the left-right direction, and connects the left and right front curved edges 13 .

The front view shape of the seat portion 11 will be described. As shown in FIGS. 2 and 11, the seat portion 11 is composed of a pair of bilaterally symmetrical support portions 15 curved so that the upper surface side is recessed. Since the seat portion 11 has a high center portion in the left-right direction and both right and left end portions, it can stably support the buttocks 51 and the base of the thighs of the seated person 50 .

As shown in FIGS. 1 and 4 , the backrest portion 16 has a shape that rises upward from the rear end portion of the seat portion 11 . The backrest portion 16 is composed of a first support portion 17 forming the center portion in the left-right direction of the backrest portion 16 and a pair of left-right symmetrical second support portions 18 forming the left and right side edge portions of the backrest portion 16. It is The left and right second support portions 18 extend obliquely forward from the left and right side edges of the first support portion 17 in a cantilever manner. The extending direction of the left and right second support portions 18 is such that the left-right interval between the left and right second support portions 18 gradually widens toward the front in a plan view.

The front surface of the backrest portion 16 serves as a support surface 19 that contacts or faces the back 52 of the seated person 50 . The front view shape of the support surface 19 (backrest portion 16) will be described. As shown in FIGS. 2 and 11, in the vertical direction (height direction), the lower end side support region 20 extending from the lower end of the backrest portion 16 to approximately 2/3 above forms a substantially trapezoid whose width gradually expands upward. . The outer peripheral edge of the upper end support region 21 above the lower end support region 20 of the backrest 16 is composed of a pair of symmetrical upper curved edge portions 22 and an upper edge gouged portion 23 . The upper curved edge portion 22 continues to the left and right side edges of the lower end support area 20 and constitutes the upper edge portion of the backrest portion 16 . The upper gouged portion has an obtuse-angled recessed shape at the center portion of the backrest portion 16 in the left-right direction, and connects the left and right upper curved edge portions 22 .

The upper curved edge portion 22 is formed only on the outer peripheral edge of the second support portion 18 . The upper edge gouged portion 23 constitutes the entire area of the upper edge portion of the first support portion 17 and a part of the upper edge portion of the second support portion 18 . The height dimension of the upper edge portion of the backrest portion 16 is maximum at the upper end of the upper curved edge portion 22 and is minimum at the lowest end of the upper edge gouged portion 23 (center of the backrest portion 16 in the left-right direction). In other words, the lowest end portion 17L of the upper edge portion of the first support portion 17 is arranged at a position lower than the uppermost end portion 18U of the upper edge portion of the second support portion 18 . The lowest end portion 17L of the upper edge portion of the first support portion 17 is positioned higher than the lower end of the upper curved edge portion 22 (upper end side support region 21) (the height at which the backrest portion 16 becomes the maximum width). The lower end of the upper curved edge 22 is at the height at which the backrest 16 is at its maximum width.

As shown in FIG. 2, the width dimension of the backrest portion 16 is maximized at the upper end of the lower end support area 20 (the lower end of the upper curved edge portion 22). The maximum width dimension of the backrest portion 16 is set slightly smaller than the maximum width dimension of the seat portion 11 . The width dimension of the backrest portion 16 is the smallest at the lower end portion 16L (that is, the rear end portion of the seat portion 11) of the backrest portion 16 (lower end side support area 20). The interval (width dimension) between the upper ends of the left and right upper curved edge portions 22 is smaller than the maximum width dimension of the backrest portion 16 . The height dimension of the backrest portion 16 is set larger than the front-rear dimension of the seat portion 11 .

As shown in FIGS. 2 and 3, the support surface 19 is composed of a first support surface 24 forming the first support portion 17 and a pair of symmetrical second support surfaces 28 forming the second support portion 18. It is The first support surface 24 is arranged in the center of the support surface 19 in the left-right direction, and has a substantially vertically long rectangular shape as a whole. As shown in FIG. 4, the upper end of the first support surface 24 forms a first upper curved surface 25 that bulges obliquely upward and forward and curves obliquely upward and rearward.

As shown in FIG. 4, the lower end portion 24L of the first support surface 24 is smoothly connected to the rear end portion of the seat portion 11, which is curved upward toward the rear. A region of the first support surface 24 below the first upper curved surface 25 serves as a first receiving surface 27 having a substantially planar shape. The first receiving surface 27 is oriented substantially vertically when the posture holder 10 is in use. The vertical dimension of the first receiving surface 27 is approximately half the total height dimension of the first supporting surface 24 .

The pair of left and right second support surfaces 28 are arranged on both left and right sides of the first support surface 24 in the support surface 19 . The second support surface 28 has a shape extending obliquely forward from the left and right side edges of the first support surface 24 . The front edge of the second support surface 28 has a curved shape that bulges forward. That is, the dimension of the second support surface 28 in the front-rear direction (extending dimension from the side edge of the first support surface 24) increases upward in the upper end support region 21 of the second support surface 28. , in the lower end side support area 20 of the second support surface 28, it becomes smaller as it goes downward.

A region of the second support surface 28 that is close to the first support surface 24 in the left-right direction serves as a second receiving surface 29 . The second receiving surface 29 has a substantially planar shape substantially parallel to the extending direction of the second support portion 18 . A peripheral portion of the second support surface 28 that surrounds the second receiving surface 29 from above, front, and below is curved so as to swell obliquely forward and inward and warp obliquely rearward.

The upper end of the second support surface 28 forms a second upper curved surface 30 that swells obliquely upward and forward and curves obliquely upward and backward. The left and right second upper curved surfaces 30 are smoothly connected to the left and right side portions of the first upper curved surface 25 . A lower end portion of the second support surface 28 is a second lower curved surface 31 that curves obliquely downward and forward.

As shown in FIGS. 3 and 11, in a plan view, a pair of left and right regions connecting the left and right side edges of the first support surface 24 and the second receiving surface 29 of the second support surface 28 in the support surface 19 are: The connection surface 32 is recessed in an arc shape. The pair of connecting surfaces 32 are bilaterally symmetrical and elongated in the vertical direction. In plan view, the curvature of the first supporting surface 24 (first receiving surface 27) and the curvature of the second supporting surface 28 (second receiving surface 29) are small values close to zero. Curvature is large. In front of the backrest portion 16, a generally trapezoidal holding space 33 opened forward is defined by a first supporting surface 24, left and right second supporting surfaces 28, and left and right connecting surfaces 32. It is

The first receiving surface 27 of the first supporting portion 17 is a region of the first supporting surface 24 against which the central portion of the back 52 of the seated person 50 in the left-right direction can come into contact when the person is seated. The second receiving surface 29 of the second supporting portion 18 is a region of the second supporting surface 28 that can come into contact with both left and right sides of the back 52 of the seated person 50 when seated. The topmost position of the first receiving surface 27 is set at a position lower than the topmost position of the second receiving surface 29 . The first receiving surface 27 is positioned so as to be sandwiched between the pair of second receiving surfaces 29 in the left-right direction. Therefore, the posture holder 10 can support the back 52 of the seated person 50 at three points with the single first receiving surface 27 and the pair of left and right second receiving surfaces 29 . These three receiving surfaces 27 and 29 have a height difference, are spaced horizontally, and are spaced forward and backward.

As shown in FIG. 12, the posture holder 10 is composed of an outer shell member 34, a cushion material 39, and an exterior sheet 40 in terms of component configuration. The outer shell member 34 is a single plate-like member made of hard synthetic resin and having a constant thickness over the entire region. The outer shell member 34 is formed in a curved shape so that its side view shape is approximately L-shaped. The outer shell member 34 includes a seat portion forming plate portion 35 forming the seat portion 11 and a backrest portion forming plate portion 36 forming the backrest portion 16 . The seat portion forming plate portion 35 has substantially the same shape as the seat portion 11 described above, and is composed of a plurality of curved plate portions curved with different curvatures. The backrest-constituting plate portion 36 has a form that rises upward from the rear end portion of the seat-constituting plate portion 35 , and separates the first support plate portion 37 that constitutes the first support portion 17 and the second support portion 18 from each other. A pair of symmetrical second support plate portions 38 are provided.

The shape of the first support plate portion 37 is substantially the same shape as the first support portion 17 and the first support surface 24 described above. A height region of the first support plate portion 37 corresponding to the first receiving surface 27 has a curved shape that bulges forward as a whole when viewed from the side. It is slightly tilted forward from the vertical direction. A region of the first support plate portion 37 corresponding to the first upper curved surface 25 is curved obliquely upward and rearward. A region of the first support plate portion 37 corresponding to the first lower curved portion 26 has a curved shape that slopes downward and bulges obliquely downward and rearward.

The pair of second support plate portions 38 extend obliquely forward from the substantially straight left and right side edges of the first support plate portion 37 and extend in a cantilever manner so that the left-right spacing between them widens forward. is. The shape of the second support plate portion 38 is substantially the same shape as the second support portion 18 and the second support surface 28 described above. A region of the second support plate portion 38 corresponding to the second receiving surface 29 has a substantially flat plate shape, and a peripheral portion of the second support plate portion 38 has a curved shape that curves obliquely rearward.

As shown in FIG. 4, the lower end portion 36L of the backrest-constituting plate portion 36 continues to the rear end portion of the seat-constituting plate portion 35, and constitutes the lower end portion 36L of the backrest-constituting plate portion 36. Only the first support plate portion 37 does. That is, the first support plate portion 37 is directly connected to the seat portion constituting plate portion 35, but the second support plate portion 38 is not directly connected to the seat portion constituting plate portion 35. First, it is connected to the seat portion forming plate portion 35 via the first support plate portion 37 .

The outer shell member 34 maintains the overall shape of the posture holder 10 and has rigidity (shape retention) that can stably hold the posture of the seated person 50 . However, when subjected to a static load caused by the weight of the seated person 50 or a dynamic load caused by a change in the sitting posture of the seated person 50, the seat should be elastically deformed to the extent that the seated posture is not affected. It has become. Specifically, the second support plate portion 38 is elastically displaced relative to the first support plate portion 37 so as to expand in the left-right direction with the left and right side edges of the first support plate portion 37 as substantial fulcrums. It is possible to

In addition, when the above static load or dynamic load is applied, the backrest component plate portion 36 (backrest portion 16) is placed against the seat portion component plate portion 35 (seat portion 11). The lower end portion 36L of the portion 36 (the rear end portion of the seat portion-constituting plate portion 35) is substantially a fulcrum. At this time, the amount of elastic deformation of the backrest-constituting plate portion 36 (the stress generated in the backrest-constituting plate portion 36) is maximized at the lower end portion 36L, which is substantially the fulcrum of the elastic displacement. At least the lower end side support region 20 of is also elastically deformed. The elastic deformation of the lower end side support region 20 of the first support plate portion 37 is preferable as means for avoiding stress concentration at the lower end portion 36L of the backrest portion-constituting plate portion 36 .

However, the second support plate portions 38 protruding from the left and right side edges of the first support plate portion 37 function as reinforcing ribs that resist the elastic deformation of the first support plate portion 37 . Therefore, as shown in FIGS. 8 to 10, the projecting dimension of the lower end side region of the second support plate portion 38 from the first support plate portion 37 is set to gradually decrease downward. Thus, when the backrest component plate portion 36 is elastically displaced in the front-rear direction with respect to the seat component plate portion 35, the lower end side region of the first support plate portion 37 is also elastically curved and deformed. there is In addition, in the first embodiment, the lower end region of the second support plate portion 38 is defined as a region extending from the lower end portion 38L of the second support plate portion 38 to at least about 1/3 of the height.

The cushion material 39 is attached so as to be laminated on the surface of the outer shell member 34 that faces the seated person 50 (the upper surface of the portion that constitutes the seat portion 11 and the front surface of the portion that constitutes the backrest portion 16). there is The cushion material 39 is made of, for example, urethane foam or the like, and is a member for avoiding discomfort caused by the buttocks 51 and the back 52 of the seated person 50 coming into contact with the hard outer shell member 34 . The thickness of the portion of the cushioning material 39 corresponding to the first receiving surface 27 is not constant in the vertical direction, but varies so as to gradually increase downward. As a result, when the posture holder 10 is placed on a horizontal surface, the first receiving surface 27 of the first supporting surface 24 is oriented substantially vertically.

The exterior sheet 40 is made of cloth, and faces the outer surface of the outer shell member 34 (the lower surface of the portion forming the seat portion 11 and the rear surface of the portion forming the backrest portion 16) and the cushion material 39 facing the seated person 50. It covers the entire surface (the upper surface of the portion that configures the seat portion 11 and the front surface of the portion that configures the backrest portion 16). When the outer shell member 34 is elastically deformed, the cushion material 39 and the outer sheet 40 are flexibly deformed.

The posture holder 10 can be used in a state where it is placed directly on the floor (not shown) or placed on a chair 53 . FIG. 12 shows a state in which the device is placed on a chair and used. When the seated person 50 sits on the posture holder 10, the buttocks 51 are supported from below by the seat part 11, the trunk of the upper half of the body is accommodated in the holding space 33, and the back 52 is supported by the backrest part 16 from behind. At this time, the portion corresponding to the lower thoracic spine of the left-right central portion of the back 52 contacts the first support surface 24 , and the left and right side portions of the back 52 contact the left and right second support surfaces 28 .

At this time, the site of contact with the second support surface 28 is positioned higher than the site of contact with the first support surface 24 and at a position forward of the site of contact with the first support surface 24. . In other words, the back 52 can support a plurality of parts at different positions in the three-dimensional direction. Also, when the seated person 50 is an adult with an average body type, the contact position with the second support surface 28 is the back side of the ribs and at a height lower than the shoulder blades.

The posture holder 10 of the first embodiment has a seat portion 11 that supports the buttocks 51 of the seated person 50 from below, and a form that rises from the rear end portion of the seat portion 11 so that the upper half of the seated person 50 can be seen from the back 52 side. A supporting backrest 16 is provided. The backrest portion 16 is arranged on both left and right sides of the first support portion 17 against which the central portion of the back 52 of the seated person 50 in the left-right direction abuts, and on both left and right sides of the back 52 of the seated person 50 . and a pair of second support portions 18 with which the parts are brought into contact with each other.

The first support portion 17 supports a relatively low central portion of the back 52 of the seated person 50 from behind, and the pair of left and right second support portions 18 are higher than the first support portion 17 of the left and right sides of the back 52 . Support the part diagonally from behind. Therefore, the seated person 50 sits in a state in which the relatively low center portion of the back 52 is placed against the first support portion 17 and the relatively high portions of the left and right sides of the back 52 are placed against the second support portion 18 . . Since the back 52 of the seated person 50 is supported by the three supporting parts 17 and 18, which are spaced apart from each other to the left and right, and have different heights, the back 52 of the seated person 50 can be supported in a posture in which the upper body is tilted to the left or right or a posture in which the upper body is twisted to the left or right. restrained from becoming Therefore, the posture holder 10 of the first embodiment can hold the upper body of the seated person 50 in a correct posture.

In addition, the first support part 17 supports a relatively low part of the back 52 of the seated person 50 (the whole or part of the range from the upper part of the lumbar spine to the lower part of the thoracic spine), and the second support part 18 supports the back 52. Since it supports the high part of the rib back (all or part of the corresponding part from the lower part of the thoracic vertebrae to the middle height of the thoracic vertebrae), when the seated person 50 puts his weight on the backrest part 16, The back 52 is supported at a plurality of locations with height differences. As a result, the upper half of the body of the seated person 50 is maintained in a correct posture such that the spine draws a proper curve when viewed from the side. Here, the correct posture is a posture in which the thoracic spine curves backward, the lumbar spine curves forward, and the sacrum and coccyx curve backward.

Further, when the upper end of the first support portion 17 is aligned with the upper end of the second support portion 18, the thoracic vertebra portion of the back 52, which is curved so as to swell rearward, is located at the same height as the first support portion 17. There is a risk that it will hit the upper end of the spine, making it difficult for the spine to draw a proper curve. As a countermeasure, the posture holder 10 of the first embodiment forms an upper edge gouged portion 23 on the upper edge of the backrest portion 16 so that the height of the upper end of the first support portion 17 is equal to that of the upper end of the second support portion 18 . Although it is made lower, when the upper edge gouged portion 23 is formed, a space is formed immediately above the first support portion 17 (that is, between the upper ends of the left and right second support portions 18). It becomes impossible to support the back 52 in the vicinity of the upper part of the support part 17 . Therefore, it is feared that a portion of the upper body of the seated person 50 above the first support portion 17 (relatively low portion of the back 52) may warp backward. Since the seated person 50 is supported by the second support portions 18 on both the left and right sides above the first support portion 17, the seated person 50 can sit in a relaxed state with an appropriately open chest.

In addition, in the seated state, the second support portion 18 is elastically displaced obliquely rearward due to the pressing force from the upper body of the seated person 50. Therefore, the elastic restoring force of the second support portion 18 (the second support plate portion 38) The pressure is felt more strongly on the left and right sides of the back 52 than on the central portion. Therefore, it is possible to prevent the upper body of the seated person 50 from being tilted to the left or right or twisted to the left or right.

In addition, since the upper end portion of the second support portion 18 is formed with a second upper curved surface 30 that is curved obliquely rearward toward the upper side, the upper half of the seated person 50 is supported by the backrest portion 16. The upper edge of the second support part 18 does not dig into the body of the seated person 50 when the seated person 50 is leaned deeply, and the seated person 50 can sit deeply on the seat part 11.例文帳に追加In addition, by sitting deeply, the left and right sides of the back 52 are firmly pressed against the second support portion 18, so that the upper body can be reliably prevented from being twisted left and right. Furthermore, since the upper end of the second support portion 18 does not bite into the body of the seated person 50, the upper part of the back 52 can be bent backward appropriately, so that the seated person 50 can be held in a correct posture. can.

The posture holder 10 also has an outer shell member 34 for maintaining its shape. The outer shell member 34 includes a seat portion forming plate portion 35 that forms the seat portion 11 and a backrest portion forming plate portion 36 that forms the backrest portion 16 . The backrest forming plate portion 36 is connected to the seat portion forming plate portion 35 so as to be elastically displaced relative to the seat portion forming plate portion 35 with the lower end portion 36L of the backrest portion forming plate portion 36 being substantially a fulcrum. Therefore, when the seated person 50 strongly presses the upper half of the body against the backrest portion 16, the backrest portion 16 is elastically displaced rearward relative to the seat portion 11 with the lower end portion 36L as a substantial fulcrum.

At this time, if stress concentrates on the lower end portion 36L of the backrest portion-constituting plate portion 36, which is the fulcrum of relative elastic displacement, there is concern that repeated stress concentration will progress deterioration and reduce durability. . As means for avoiding concentration of stress on the lower end portion 36L of the backrest-constituting plate portion 36, not only the lower end portion 36L of the backrest-constituting plate portion 36 but also at least the lower end side of the backrest-constituting plate portion 36 It is preferred that the regions are also elastically deformed together.

However, the backrest-constituting plate portion 36 protrudes obliquely forward from the first support plate portion 37 forming the first support portion 17 and the left and right side edges of the first support plate portion 37 to form the second support portion 18 . Since it is composed of the pair of left and right second support plate portions 38, it is difficult to deform. Therefore, the projecting dimension of the lower end side region of the second support plate portion 38 from the first support plate portion 37 is made to gradually decrease downward. As a result, not only the lower end portion 36L but also the lower end side region of the backrest portion forming plate portion 36 is elastically deformed, so that the concentration of stress on the lower end portion 36L of the backrest portion forming plate portion 36 can be prevented. Since the upper end region of the backrest-constituting plate portion 36 has higher flexural rigidity and is less elastically deformable than the lower end region, the upper body of the seated person 50 can be stably held.

A first support surface 24 of the first support portion 17 facing the back 52 and a second support surface 28 of the second support portion 18 facing the back 52 are connected via a pair of left and right connecting surfaces 32 . The curvature of the first supporting surface 24 and the curvature of the second supporting surface 28 are set smaller than the curvature of the connecting surface 32 in plan view. According to this configuration, since the back 52 does not hit the joint surface 32 having a large curvature, the upper body of the seated person 50 is stabilized at three points, the first support surface 24 and the pair of left and right second support surfaces 28 . can support.

<Other Examples>
The present invention is not limited to the embodiments explained by the above description and drawings, and the following embodiments are also included in the technical scope of the present invention.
(1) In the posture retainer of the above embodiment, the seat portion and the backrest portion are integrally formed. can be anything.
(2) In the above embodiment, the upper end portion of the second support portion is curved so as to bend obliquely rearward as it goes upward, but the upper end portion of the second support portion is not curved. good too.
(3) The backrest-constituting plate portion of the above embodiment is formed by integrally forming the first support plate portion and the second support plate portion. It may be configured by assembling the first support plate portion and the second support plate portion.
(4) In the above-described embodiment, the projection dimension of the lower end region of the second support plate portion from the first support plate portion gradually decreases toward the bottom. The projection dimension from the first support plate portion may be substantially constant in the vertical direction.
(5) In the above embodiment, the seat portion and the backrest portion are elastically displaced relative to each other, but the seat portion and the backrest portion may not be displaced relative to each other.
(6) In the above embodiment, the first support surface and the second support surface are connected via a connecting surface having a large curvature, and the back of the seated person is supported at three locations spaced apart from each other. Without being limited to this, the curvature of the connecting surface may be made smaller than that of the first embodiment, and the back may be supported in a laterally continuous region from the second support surface on the left side to the second support surface on the right side. Even in this case, it is possible to prevent the upper body of the seated person from being tilted to the left or right or twisted to the left or right.
(7) In the above embodiment, the upper edge of the first support is formed with a gouged portion so that there is a space in the vicinity of the upper part of the first support (between the upper ends of the left and right second supports). However, the height of the upper end of the first supporting portion and the height of the upper end of the second supporting portion may be substantially the same without forming the upper edge gouged portion. Even if the upper edge of the backrest has a constant height over a wide range, the degree of backward inclination of the upper edge of the backrest corresponding to the upper end of the first support is determined. If the depth is deeper than the upper end of the second support, it is possible to prevent the center of the back in the left-right direction from strongly hitting the upper edge of the backrest when the back is bent backward.

DESCRIPTION OF SYMBOLS 10... Posture holder 11... Seat part 16... Backrest part 17... First support part 18... Second support part 17L... Bottom end part of the upper edge part of the first support part 18U... Upper edge part of the second support part 24 First support surface 28 Second support surface 32 Connecting surface 35 Seat portion forming plate portion 36 Backrest portion forming plate portion 36L Lower end portion of backrest portion forming plate portion 37 First Support plate portion 38 Second support plate portion 50 Seated person 51 Buttocks 52 Back

Claims (4)

a seat;
a backrest rising from the rear end of the seat;
a first support portion that constitutes the backrest portion and that abuts the central portion of the back of the seated person in the left-right direction;
A pair of second support portions that constitute the backrest portion, are arranged on both left and right sides of the first support portion, and make contact with the left and right sides of the back of the seated person,
A posture holder, wherein the lowermost end of the upper edge of the first support is located at a position lower than the uppermost end of the upper edge of the second support. 2. The posture holder according to claim 1, wherein the upper end portion of said second support portion is curved so as to warp obliquely rearward as it goes upward. The seat portion constituting plate portion constituting the seat portion and the backrest portion constituting plate portion constituting the backrest portion are elastically displaced relative to each other with the lower end portion of the backrest portion constituting plate portion serving as a substantial fulcrum. in a row,
The backrest portion-constituting plate portion includes a first support plate portion forming the first support portion, and a second support plate portion protruding obliquely forward from left and right side edges of the first support plate portion to form the second support portion. and a support plate portion,
3. The posture holder according to claim 1, wherein a projection dimension of the lower end side region of the second support plate portion from the first support plate portion gradually decreases downward. A first supporting surface of the first supporting portion facing the back and a second supporting surface of the second supporting portion facing the back are connected via a pair of left and right connecting surfaces,
The posture holder according to any one of claims 1 to 3, wherein the curvature of the first support surface and the curvature of the second support surface are smaller than the curvature of the joint surface in plan view.

Images